Automatic brake slack adjuster for railroad car brake riggings



May 13, 1952 W. .1. socKELl. 2,596,301

AUTOMATIC BRAKE SLACK ADJUSTER FOR RAILROAD CAR BRAKE RIGGINGS A medFeb. 24, 195o 2 SHEETS- SHEET 1 May 13, 1952 w. J. socKELL AUTOMATICBRAKE SLACK ADJUSTER FOR RAILROAD CAR BRAKE' RIGGINGS 2 SHEETS-SHEET 2Filed Feb, 24, 1950 Patented May 13, 1952 nUToMg'rrc BRAKE ammalano@sLAcii nD'JUs'rEltf Fon BRAKE alccINcs "WuimlJsockltnalighm: c.npplientn'frebsuary 24, 19st, srallNosifissaa This inventionrelates toanvattachmentffor use with a conventionalair,-iarake rigging cf Aarailroad car, particularly a freight-canto,- provide an automatic slackadiusting :means f for staking up slack in fthe brake -unit of ueachcar-truck resulting from fwearonthe lorakefshoesA automatically wheneverthe piston travelfofa-brake cylinder exceeds fa predetermineddistance-forcenstantly and automatically maintaining `the brakes inproper operating-adjustment.

The present invention is primar-ily distinguished from prior devices forautomatically -adjusting the brakes of freight cars in'that--thebrake-ad justor is operated by direetconnection withfthe air brakecylinder of thecar rather than-being directly connected to the air brakeline thus eliminating additional valves andregulating apparatusotherwise required-and positivelyi preventing inadvertent application iof cthe brakes -in an emergency position.

Still afurther*objectief-'the invention iszto provide an automaticbrakeeadjustor whichymay be readily released manually when brake-shoesare replaced Vand Vwhich-will thereafterfeffect proper adjustment forthenew-brake shoes.

Still another obi ect of the invention isftov, provide an automaticbra-kefslack 4adjusting apparatus of extremelysimple-constructioninvolvngfa minimum ofi parts and which* may-tbe`quicklyand easily mounted on arailroadf Garland `connected. operativelyto `the *brakerggingfthreon Various other vobjects --and advantages of"the invention will hereinafter become more fully apparent from thefollowing description of the drawings, illustratingl -a l presently `prferred em- 35 bodiment thereof applied to-a'vconventional air brakerigging of arailroadearfand wherein:

Figure 1 is a top.planview.ofthe'undercarriage of a freight carillustrating alconventionalair brake rigging and showing the,atoinaticbrake slack adjustor applied thereto;

Figure 2 is a longitudinallsetional"view,"ptly in side elevationthereof;

Figure 3 is a cross `sectioal`-viewtakensbstantially along 'a `pls'alriewas' indicated "by the,v line,

3-3 ofFigure 1;

Figure 4 is an 'enlarged fragmentary' planiview, partly in section,illustrating the 'automatic brake slack adjuster and' certain of'thepartsassociated therewith; i

Figure 5 is an enlarged fragmentaryfsid'eeie'vational View, partlyinsection of"aportion"6f the automatic slack adjuster, `taken"substantially along a "plane as 'indicatdfbyf theline' 545 "of Aliigure4, and

(cljis-cm ,t

f2 :iF-igurev -isa -cross sectional View thereof taken @substantiallyalong Ya plane as indicated by the line-'6 6 of Figure 5.

fRef-errfing more specifically to the drawings for i 5 `@thea purpose,of illustrating a -r preferred applica- Ytion-andl user oftheautomatic1brake` slack ad- `j-ustorfdesignatedgenerally 8 andcomprising the inventiona part ofi-the undercarriage of a freight:year-andthebrake-rigging thereof has been' illus- .10trated-finfthedrawings including a center sil1"'9 which conventionallysupported adjacent its ends on Athe car'trucksfdesignated generallyl.The conventional air line ll of the-airbrake system extendslongitudinally ofthe center sill y15i-and is lsuitably supported`thereby orby other .paitsof thecan Anot shown. The air line'l l'hasalranch I2 which isconnectedto a triple valve [3,ofconventionalconstruction. Two conduits I4 land ljextendbetween-the4triple valve `|3 20 andthe end cfa reservoir 16, one end'of'whichportion of the lever 34.

Y the teeth 44.

Each of the levers 25 and 26 is pivotally connected near its lower endto a transversely disposed brake beam 30, intermediate of the ends ofsaid brake beam and by an extension 3| thereof. Each brake beam carriesa brake shoe 32 on each end thereof and the shoes of each brake beam arearranged to engage transversely aligned wheels 33 of the truck I9 whenthe pull rod 24 is displaced from right to left of Figure 1 and whichcauses the brake beams 3|] to be displaced away from one another in aconventional manner for applying the brakes or for displacing the fourbrake shoes 32 into engagement with the four truck wheels 33.

The other truck I at the left of Figure 1 has a corresponding brake unitincluding a pull rod 24a, live lever 25a, dead lever 26a, bracket 21a,bottom rod 29a, brake beams 30a, and brake shoes 32a. A lever 34 issupported beneath the center sill 9 and substantially transverselythereof by a yoke member 23, in the same manner as the lever 22 and ispivotally connected at Vone of its ends to the other end of the pull rod24a. A connecting rod 35 extends 1ongitudinally beneath the center sill9 and has one end pivotally connected at 36 to the intermediate portionof the'lever 22 and its opposite end pivotally connected at 31 to theintermediate The parts previously described are all of conventionalconstruction and have been illustrated and described merely to afford abetter understanding of the brake slack adjustor 8.

The usual stationary pivot or fulcrum for the lever 34 is omitted andreplaced by a part of the automatic slack adjustor 3, which partincludes an adjustor unit, designated 38 and which `substantiallycorresponds in construction to my prior U. S. Patent 2,495,990 to whichreference ismade for a more complete disclosure. TheV adjustor unit 38as best illustrated in Figures and 6 includes a bracket 39 having ahorizontal flange 40 which is secured by fastenings 4|, to the centersill 9 to support the bracket 39 in a depending position with respectthereto. The bracket 39 defines an upwardly opening channel 42 throughwhich a rack bar 43 slidably extends. The upwardly facing teeth of therack bar 43 are all inclined in the same direction as seen at 44 andtoward the lever 34."

A pawl 45 is pivotally mounted in the channel of the bracket 39 on a pin46 and has its free end disposed to engage between two of the teeth 44and is held in engagement therewith by a tumbler 41 which is pivotallymounted in the bracket 39 on a pin 48 and which bears on the pawl 45. Asseen in Figure 5, the rack b'ar 43 may be displaced from Vright to leftof Figure 5 or of Figure 2, thus in a direction away from the locationof the lever 34, as seen in Figures 1 and 2 and in so moving the freeend of the pawl45 will ride over the inclined surfaces of the teeth 44.However, the pawl will positively prevent the rack bar 43 from slidingin the opposite direction unless the pawl 45 is manually raised byinserting the ngerthrough the opening 49 in one wall of the bracket 39for raising the free end of the pawl out of engagement with One end ofthe rack bar 43 is pivotally connected at 50 tothe lever 34, near itsopposite end and remote to the end thereof which is connected to thepull rod 24a.

The connecting rod 35 is pivoted to the lever 34 substantiallyintermediate of the pivot 50 and of the pivot of the pull rod 24a tosaid lever 34.

A piston rod 5|, constituting a part of the slack adjustor, extendsreciprocally through one end of an adjuster cylinder 52 and has anexposed end pivoted at 53 to the lever 34 intermediate of the pivots 31and 59. The adjustor cylinder 52 is supported beneath the center sill 9by a bracket 54, as seen in Figure 3. A piston 55 is reciprocallydisposed in the cylinder 52 and is connected to the opposite end of thepiston rod 5|. A pipe or conduit 55 has one end connected to thecylinder 52 and opens into the end thereof opposite the end throughwhich the piston rod 5| reciprocally extends. The opposite end of thepipe 56 is connected to and communicates with the brake Vcylinder i8 ata point intermediate of its ends and which is preferably spacedsubstantially seven and one-half inches from the normal, inoperativeposition of the piston I9, as illustrated in Figure 4. The piston I9 isnormally held in its inoperative position by a spring I9a, constitutinga part ofthe conventional brake rigging and the cylinder I3 is providedwith a vent port Ia, likewise constituting a conventional part thereofand which is disposed near the end of the cylinder,

remote to the end thereof to whichA the pipe Il is connected.

VWhen the air brakes are normally applied by operation of the triplevalve I3, in a conventional rnanner and under control of the engineer,air is admitted to the line I'I exertinga pressure on the Vpiston I9 fordisplacing it fromj left to right of Figure 4. The normal travel of thepiston I9 in applying the brakes is lessAthan seven and one-half inchesso that the end of the pipe 56 which connects with the brake'cylinder I8is not exposed by travel of the piston VI 9 therebeyond. When the pistonI9 is thusmoved from left to right the lever 22 is caused to rock on thepivot 36 as a fulcrum in a counterclockwise direction as seen in Figurel for applying the brakes of the right-hand truck I0, as previouslydescribed. However, throughthe connecting rod Y 35 the brakes oftheleft-ha'nd truck IU are likewise Vsimultaneously applied and with thesame pressure due to the'fact that the lever 22 will also be displacedlongitudinally from left to right of Figure l as it is rockedcounterclockwise Y tions similarly to the normal stationary fulcrum ofthe lever 34, since the rack bar 43 will'be prevented by the pawl 45from moving from left to right of Figure l. Accordingly, as the lever 34rocks counterclockwise on its pivo't50'a pull will be exerted 4from leftto right on the pull rod 24a. for similarly applying the brakes of theleft-hand truck In, in the manner'as previously described in detail inreferenceto the brakes of the right-hand truck IQ. The precedingdescription of the operation of Vthe bralnesisconventional. However,should the brake V-shoes 32 or 32a be worn or should either of said,sets of brake shoes be worn su'iciently to afford sufiicient slack inthe brake rigging soth'at normal air pressure in the line I1 will movethe piston I9 a distance greater than seven and one-half inches from itsnormal, at rest position of Figure 4, this movement of the piston I9from Aleft to right of Figure 4 for a distance of 4greater than sevenand one-half inches will cause thepiston to move beyond and expose thepipe 56 so that air can escape from the brake cylinder |18 toi-cffeeegeoi the fedjustorcyiinder1152. This win Ycause Jthe piston-*55and piston Yrod 35 l to'\^beldisplaced`from :right to ."left'of4LEigureMIwa-nd when thisoccurs the1 lever A`3ftwilli'be moved ffrom"right to' leftl of Figures `l and 4. carrying with it the'rak'bari-43 1whichwillfsliidein the `same direction through the bracket 39. The pawl45 will be displaced upwardly to allow this rmovement of the rack bar`43` but vwillprevent said rack..bar. from moving in the oppositedirection. so .that theffi'ilcrum point E! of the lever 34 will thus bedisplaced from right to leftof'ligure 1"th'ereby increasing the distancebetween the fulcrum points 2l and -ilr-totakeup the slack inthe brakeriggingsince `"this will tend to displactheend of theilever; 3ft

Awhich-.is connected'to thepull 'rod 24aifro'mleft toxright `of `Figurei 1 whichivill [displace the con- `necting rod 3`5'in the oppositedirection dueto the fact that the'lever'3`4 Vwillthen be disposed morenearly crosswise of the center sill 9. This displacement of theconnecting rod 35 from right to left of Figure 1 will cause the lever 22to be rocked counterclockwise on its pivot 2l for taking up slack in thebrake unit of the right-hand truck lil by the pull thus exerted on thepull rod 2t. After this adjustment has been accomplished the unit 38will retain the parts in their adjusted positions and the air will thenescape back through the pipe 5S to the cylinder IB, normally before thebrakes are knocked off and the piston I9 commences its movement to theright and back to its position of Figure 4 or, in any event, the air mayescape through the vent port Ilia, so that the piston 55 and piston rod5l are normally disposed for free sliding movement in the adjustorcylinder 52 and thus will not interfere with the normal swingingmovement of the lever 34 in the application or release of the brakes,After the brake shoes have been worn sufliciently to requirereplacement, the pawl fle is manually raised, as previously described,and the end of the lever 34 beyond and adjacent the pivot Suis graspedas a handle for swinging said lever to the right or clockwise as seen inFigure l and with the rack bar 43 moving in the same direction, afterwhich when the brakes are initially applied the automatic brake adjustor3 will initially function to automatically obtain a correct initialadjustment.

Various modications and changes are contemplated and may obviously beresorted to, without departing from the spirit or scope of the inventionas hereinafter dened by the appended claims.

l claim as my invention:

1. An automatic brake slack adjuster for a railroad car comprising, incombination with an air brake rigging of a railroad car including abrake cylinder responsive to air pressure in the air line connected toan end of the brake cylinder for rocking link connected levers forapplying the brakes of the four wheels of each truck of a railroad car;a rack bar pivotally connected at one of its ends to one lever of thebrake rigging and forming the normal stationary pivot of said lever, abracket reciprocally supporting said rack bar, a pawl mounted pivotallyin said bracket for engaging the rack bar teeth, said rack bar teethbeing inclined all in one direction for free sliding movement of therack bar through said bracket in one direction, said pawl holding therack bar against movement relatively to the bracket in the oppositedirection, an adjustor cylinder supported by a part of the railroad car,a piston reciprocally disposed in the adjustor cylinder, a

piston reciprocally through *one-end of the`v adjustor cylindereandpivotallyfconnected -tofsaid lever .between the "rack "bar iplvtrarfd.the link connection Lto "said 'l lever, and uan A`air epipe Gextendingffrom the .oppositeend-f :thefadjustor cylinder. totheintermediateportionof fthe" brake cylinder, the -.brake piston being normallydisposed in lthe brake cylinder "between "the iconnections ofthefairll'ine and ltheair pipe :tol said brake cylinder and beingimovable-beyondthe connection. of the. air pipe to.the brake cylinderwhen .the ..brakes-are .applied f i an excess `amount .of -brake .slackexists .whereby comi.pressed air `lfrom the i train air .line will'.pass through--thegbrake Acylinder and ainpipeltoithe adjuster lcylinder for Ymoving i. the -radjustor cylinderf` piston andipistonl.rodtofar-projected .position to displace the lever connected to saidpiston rod away from the adjustor cylinder for taking up the brake slackand for moving the rack bar through its supporting bracket in said firstmentioned direction of movement.

2. An automatic brake slack adjuster for air brake riggings of railwaycars comprising a rack bar, means for reciprocally supporting said rackbar for sliding movement in a direction longitudinally of a railroadcar, a pawl supported by said means and engaging the teeth of the rackbar to permit free sliding movement of the rack bar in one directionrelatively to said means and to prevent sliding movement of the rack barin the opposite direction, one end of said! rack bar being pivotallyconnected to a first brake rigging lever which is adapted to operate thebrakes of one truck of the car and which is connected to a second brakerigging lever for operating the brakes of the other car truck by alongitudinally extending connecting rod, an adjustor cylinder supportedby the car between said brake rigging levers, a .piston reciprocallymounted in the adjustor cylinder, a piston rod fixed to and projectingfrom said piston reciprocally through one end of the adjustor cylinderand having an outer end pivotally connected to said first brake leverbetween the points of connection of the connecting rod and rack bar tothe :first brake rigging lever, an air line extending from the oppositeend of the adjustor cylinder and adapted to be connected to theintermediate portion of a brake cylinder containing a piston and apiston rod which is connected to said second brake lever beyond one endof said brake cylinder and which brake cylinder is, provided with an airinlet from the air line of a car at its opposite end, the piston of saidbrake cylinder being normally disposed between the brake cylinder airinlet and the connection of the air line to the brake cylinder, thepoint of connection of the air line to the brake cylinder being spacedfrom the inoperative position of the brake piston a distance exceedingthe distance of normal travel of the brake piston in applying the brakeswhereby when the brake piston exceeds its normal travel due to slackexisting in the brake rigging said piston will move ybeyond the point ofconnection of the air line to the brake cylinder so that air underpressure will ilow from the brake cylinder to the adjustor cylinder topro-ject the adjuster cylinder piston for displacing the rst brake leveraway from the adjustor cylinder, said rack bar sliding freely throughsaid means relatively to the pawl when the first brake lever isdisplaced away from the adjustor cylinder and said pawl preventingmovement of the rackVba-r in the opposite drectionand movement of thepivot pointof the rack bar and first brake lever toward the adjustorcylinder.

3. An automatic brakev slackV adjustor as in claim 2, said rst leverbeing connected to its truck brake rigging at the end thereof remote tothe pivot of the rack bar to the rst lever, the connection oftheadjustor cylinder piston rod to said first lever being disposed adjacentthe pivot ofthe rack bar and between said rack bar pivot and the pivotof thetruck brake rigging to said lever.

4; An automatic brake slack adjustor as in claim 2, said rst lever beingconnected to its truck brake rigging at the end thereof remote to thepivot of the rack bar to the first lever, the connection of the adjustorcylinder piston rod to said first lever being disposed adjacent thepivot of the rack bar and between said rack bar REFERENCES CITED Thefollowing references are of record in the le of this patent:

YUNITED STATES PATENTS Number Name Date 1,251,642 Christensen Jan. 1,1918 1,522,275 Sauvage Jan. 6, 1925 1,825,366 Sauvage Sept. 29, 19311,845,070 Anderson Feb. 16, 1932 2,495,990 Sockell Jan. 31, 1950

